Getting small compact powerful Drill?

I'm looking for a small 12v style drill that is long & skinny (maybe 20-30cm long), so it can get into tight places without the battery pack getting in the way. Or even better a drill that runs on a 12v brick style power supply. I just hate batteries as they are expensive & lose alot of their capacity after just a few years.

I can't seem to find anything like described, unless they have a specific name?

If anyone has some suggestions, Thanks. :)